Method of manufacturing a thin-film magnetic head

ABSTRACT

A method of manufacturing a thin-film magnetic head, the thin-film magnetic head including a magnetoresistive element, first and second shield layers for shielding the magnetoresistive element, a first shield gap film provided between the magnetoresistive element and the first shield layer, and a second shield gap film provided between the magnetoresistive element and the second shield layer. The method includes the steps of forming the first shield layer, forming the first shield gap film on the first shield layer, forming the magnetoresistive element on the first shield gap film, forming the second shield gap film on the magnetoresistive element, and forming the second shield layer on the second shield gap film. At least one of the first and second shield gap films is formed by stacking a plurality of insulating films formed by chemical vapor deposition.

This is a Division of application Ser. No. 09/748,207, filed Dec. 27,2000, now U.S. Pat. No. 6,747,851, issued Jun. 8, 2004. The entiredisclosure of the prior application is hereby incorporated by referenceherein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to a thin-film magnetic head having atleast one of an induction-type electromagnetic transducer and amagnetoresistive element, and to a method of manufacturing such athin-film magnetic head.

2. Description of Related Art

Performance improvements in thin-film magnetic heads have been sought asa real recording density of hard disk drives has increased. Suchthin-film magnetic heads include composite thin-film magnetic heads thathave been widely used. A composite head is made of a layered structureincluding a recording head having an induction magnetic transducer forwriting and a reproducing head having a magnetoresistive (MR) elementfor reading. MR elements include an anisotropic magnetoresistive (AMR)element that utilizes the AMR effect and a giant magnetoresistive (GMR)element that utilizes the GMR effect. A reproducing head using an AMRelement is called an AMR head or simply an MR head. A reproducing headusing a GMR element is called a GMR head. An AMR head is used as areproducing head where a real density is more than 1 gigabit per squareinch. A GMR head is used as a reproducing head where a real density ismore than 3 gigabits per square inch. It is GMR heads that have beenmost widely used recently.

The performance of the reproducing head is improved by replacing the AMRfilm with a GMR film and the like having an excellent magnetoresistivesensitivity. Alternatively, a pattern width such as the reproducingtrack width and the MR height, in particular, may be optimized. The MRheight is the length (height) between an end of the MR element locatedin the air bearing surface and the other end. The air bearing surface isa surface of the thin-film magnetic head facing toward a magneticrecording medium.

Performance improvements in a recording head are also required as theperformance of a reproducing head is improved. It is required toincrease the recording track density in order to increase the a realdensity among the performance characteristics of the recording head. Toachieve this, it is required to implement a recording head of a narrowtrack structure wherein the width of top and bottom poles sandwichingthe recording gap layer on a side of the air bearing surface is reduceddown to microns or a submicron order. This width is one of the factorsthat determine the recording head performance. Semiconductor processtechniques are utilized to implement such a structure. Another factor isa pattern width such as the throat height, in particular. The throatheight is the length (height) of pole portions, that is, portions ofmagnetic pole layers facing each other with a recording gap layer inbetween, between the air-bearing-surface-side end and the other end. Areduction in throat height is desired in order to improve the recordinghead performance. The throat height is controlled by an amount oflapping when the air bearing surface is processed.

As thus described, it is important to fabricate well-balanced recordingand reproducing heads to improve the performance of the thin-filmmagnetic head.

In order to implement a thin-film magnetic head that achieves highrecording density, the requirements for the reproducing head include areduction in reproducing track width, an increase in reproducing output,and a reduction in noise. The requirements for the recording headinclude a reduction in recording track width, an improvement inoverwrite property that is a parameter indicating one of characteristicswhen data is written over existing data, and an improvement in nonlineartransition shift (NLTS).

Reference is now made to FIG. 16A to FIG. 22A and FIG. 16B to FIG. 22Bto describe an example of a manufacturing method of a related-artthin-film magnetic head element. FIG. 16A to FIG. 22A are cross sectionseach orthogonal to the air bearing surface. FIG. 16B to FIG. 22B arecross sections of the pole portions each parallel to the air bearingsurface.

According to the manufacturing method, as shown in FIG. 16A and FIG.16B, an insulating layer 102 made of alumina (Al₂O₃), for example,having a thickness of about 5 to 10 μm, is deposited on a substrate 101made of aluminum oxide and titanium carbide (Al₂O₃-TiC), for example.Next, on the insulating layer 102, a bottom shield layer 103 made of amagnetic material and having a thickness of 2 to 3 μm, for example, isformed for a reproducing head.

Next, as shown in FIG. 17A and FIG. 17B, a shield gap film 104 a made ofan insulating material such as alumina and having a thickness of 10 to20 nm, for example, is formed through sputtering, for example, on thebottom shield layer 103. Next, a shield gap film 104 b made of aninsulating material such as alumina and having a thickness of 100 nm,for example, is formed through sputtering, for example, on the shieldgap film 104 a except a region where a GMR element described later willbe formed. The shield gap film 104 b is provided for preventing a shortcircuit between the GMR element and the bottom shield layer 103.

Next, on the shield gap film 104 b, a film having a thickness of 40 to50 nm, for example, to make up the GMR element for reproduction isformed through a method such as sputtering. This film is etched with aphotoresist pattern not shown as a mask to form the GMR element 105.

Next, a pair of conductive layers (that may be called leads) 106 areformed by liftoff through the use of the above-mentioned photoresistpattern. The conductive layers 106 are electrically connected to the GMRelement 105. The photoresist pattern is then removed.

Next, as shown in FIG. 18A and FIG. 18B, a shield gap film 107 a made ofan insulating material such as alumina and having a thickness of 10 to20 nm, for example, is formed through sputtering, for example, on theshield gap films 104 a and 104 b, the GMR element 105 and the conductivelayers 106. The GMR element 105 is embedded in the shield gap films 104a and 107 a. Next, a shield gap film 107 b made of an insulatingmaterial such as alumina and having a thickness of 100 nm, for example,is formed through a method such as sputtering on the shield gap film 107a except the neighborhood of the GMR element 105.

Next, as shown in FIG. 19A and FIG. 19B, on the shield gap films 107 aand 107 b, a top-shield-layer-cum-bottom-pole-layer (called a top shieldlayer in the following description) 108 is formed. The top shield layer108 has a thickness of about 3 μm and is made of a magnetic material andused for both the reproducing head and the recording head.

Next, as shown in FIG. 20A and FIG. 20B, a recording gap layer 109 madeof an insulating film such as an alumina film and having a thickness of0.2 μm, for example, is formed on the top shield layer 108. Next, aportion of the recording gap layer 109 located in the center of theregion where a thin-film coil described later is to be formed is etchedto form a contact hole for making a magnetic path. Next, a top pole tip110 for the recording head is formed on the recording gap layer 109 inthe pole portion. The top pole tip 110 is made of a magnetic materialand has a thickness of 1.0 to 1.5 μm. At the same time, a magnetic layer119 made of a magnetic material is formed for making the magnetic pathin the contact hole for making the magnetic path.

Next, the recording gap layer 109 and a part of the top shield layer 108are etched through ion milling, using the top pole tip 110 as a mask. Asshown in FIG. 20B, the structure is called a trim structure wherein thesidewalls of the top pole portion (the top pole tip 110), the recordinggap layer 109, and a part of the top shield layer 108 are formedvertically in a self-aligned manner.

Next, an insulating layer 111 of alumina, for example, having athickness of about 3 μm is formed over the entire surface. Theinsulating layer 111 is polished to the surfaces of the top pole tip 110and the magnetic layer 119 and flattened.

Next, as shown in FIG. 21A and FIG. 21B, on the flattened insulatinglayer 111 a first layer 112 of the thin-film coil is made for theinduction-type recording head. The first layer 112 of the coil is madeof copper (Cu), for example. Next, a photoresist layer 113 is formedinto a specific shape on the insulating layer 111 and the first layer112 of the coil. Next, a second layer 114 of the thin-film coil isformed on the photoresist layer 113. Next, a photoresist layer 115 isformed into a specific shape on the photoresist layer 113 and the secondlayer 114 of the coil.

Next, as shown in FIG. 22A and FIG. 22B, a top pole layer 116 for therecording head is formed on the top pole tip 110, the photoresist layers113 and 115 and the magnetic layer 119. The top pole layer 116 is madeof a magnetic material such as Permalloy. Next, an overcoat layer 117 ofalumina, for example, is formed to cover the top pole layer 116.Finally, machine processing of the slider including the forgoing layersis performed to form the air bearing surface 118 of the thin-filmmagnetic head including the recording head and the reproducing head. Thethin-film magnetic head is thus completed.

FIG. 23 is a top view of the thin-film magnetic head shown in FIG. 22Aand FIG. 22B. The overcoat layer 117 and the other insulating layers andfilm are omitted in FIG. 27.

In order to improve the performance characteristics of a hard diskdrive, such as a real recording density, in particular, a method ofincreasing linear recording density and a method of increasing trackdensity may be taken. To design a high-performance hard disk drive,specific measures taken for implementing the recording head, thereproducing head or the thin-film magnetic head as a whole depend onwhether linear recording density or track density is emphasized. Thatis, if priority is given to track density, a reduction in track width isrequired for both recording head and reproducing head, for example. Ifpriority is given to linear recording density, it is required for thereproducing head to improve the reproducing output and to reduce thehalf width of the reproducing output. Moreover, it is required to reducethe distance between the hard disk platter and the slider (hereinaftercalled a magnetic space). To achieve a real density of 20 to 30 gigabitsper square inch, a magnetic space of 15 to 25 nm, for example, isrequired.

Consideration will now be given to the measures taken when priority isgiven to linear recording density. Among the factors that contribute toimprovements in linear recording density, a reduction in magnetic spaceis achieved by reducing the amount of floating of the slider. The amountof floating of the slider depends mainly on the design, processingmethod, lapping method and so on of the slider.

Among the factors that contribute to improvements in linear recordingdensity, an improvement in reproducing output is achieved mainly byreplacing the AMR film with a GMR film and the like having an excellentmagnetoresistive sensitivity. It is known that another factor, that is,a reduction in half width of the reading output, is achieved by reducingthe distance between the bottom shield layer and the top shield layer(hereinafter called the shield gap length). It is possible to controlthe shield gap length it the steps of manufacturing the thin-filmmagnetic head.

The problems arising when the shield gap length is reduced will now bedescribed. To implement a real recording density of about 10 gigabitsper square inch, an appropriate shield gap length is 0.11 to 0.14 μm(110 to 140 nm). However, a shield gap length of 0.07 to 0.09 μm (70 to90 nm) is required for implementing a real recording density of 30 to 40gigabits per square inch.

It is difficult to reduce the thickness of the MR element since thisthickness is determined by factors such as the reading output required.Therefore, in order to reduce the shield gap length, it is required toreduce the thickness of the shield gap film provided between the MRelement and the bottom shield layer, and the thickness of the shield gapfilm provided between the MR element and the top shield layer.

A case is assumed wherein a shield gap length of 60 to 70 nm is requiredto implement a real recording density of 40 gigabits per square inch. Inthis case, if the thickness of the MR element is 40 nm, the thickness ofthe shield gap films each of which is provided between the MR elementand the bottom shield layer and between the MR element and the topshield layer, respectively, is required to be 10 to 15 nm.

In prior art the shield gap film is made of an alumina film formedthrough sputtering performed in a plasma atmosphere through the use ofan apparatus such as a radio frequency (RF) sputtering apparatus or anelectron cyclotron resonance (ECR) sputtering apparatus.

However, a reduction in the thickness of the prior-art shield gap filmformed through sputtering is limited to about 20 nm. That is, if thethickness of the prior-art shield gap film is smaller than 20 nm, theinsulation strength is 5 to 7 volts or smaller so that static damage islikely to occur. If the thickness of the prior-art shield gap film isreduced down to about 10 to 15 nm, not only the insulation strength ismade smaller but also pinholes are likely to occur. If static damage isdone to the shield gap film or pinholes are made in the shield gap film,a short circuit is developed between the MR element and the bottomshield layer or the top shield layer. As a result, the reading outputsignal carries noise, and it is impossible to obtain a proper readingoutput signal in some cases.

In addition, the prior-art shield gap film exhibits bad step coverage.Therefore, pinholes or faulty insulation frequently occurs in portionshaving projections and depressions, in particular, such as theneighborhood of the pattern edge of the MR element or the leadsconnected to the MR element.

As thus described, it is difficult in prior art to form the shield gapfilm that is thin and exhibits high qualities, that is, closely packedand has an even thickness, greater insulation strength and excellentstep coverage. Therefore, it is difficult to reduce the shield gaplength of the prior art thin-film magnetic head, and to reduce the halfwidth of the reading output and to improve the recording density. Inaddition, since it is difficult in prior art to form a high-quality andthin shield gap film, the yield of thin-film magnetic heads for highdensity recording is low.

Although the problems arising when the shield gap film is formed havebeen described so far, similar problems are found in formation of layerssuch as the recording gap layer, an insulating film of a thin-filmmagnetic head wherein the recording head and the reproducing head areisolated from each other by the insulating film, or an insulating layerfor isolating turns of the coil.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a thin-film magnetic headand a method of manufacturing the same for improving the performancecharacteristics and the yield by providing a high-quality insulatingfilm.

A first thin-film magnetic head of the invention comprises: a mediumfacing surface that faces toward a recording medium; a magnetoresistiveelement; a first shield layer and a second shield layer for shieldingthe magnetoresistive element, the shield layers having portions locatedon a side of the medium facing surface and opposed to each other, themagnetoresistive element being placed between these portions of theshield layers; a first shield gap film, provided between themagnetoresistive element and the first shield layer, for insulating themagnetoresistive element and the first shield layer from each other; anda second shield gap film, provided between the magnetoresistive elementand the second shield layer, for insulating the magnetoresistive elementand the second shield layer from each other. At least one of the firstand second shield gap films is made of a plurality of insulating filmsstacked that are formed by chemical vapor deposition.

A second thin-film magnetic head of the invention comprises: a mediumfacing surface that faces toward a recording medium; a first magneticlayer including a pole portion and a second magnetic layer including apole portion, the first and second magnetic layers being magneticallycoupled to each other, the pole portions being opposed to each other andplaced in regions of the magnetic layers on a side of the medium facingsurface, each of the magnetic layers including at least one layer; a gaplayer provided between the pole portions of the first and secondmagnetic layers; and a thin-film coil at least a part of which is placedbetween the first and second magnetic layers, the at least part of thecoil being insulated from the first and second magnetic layers. The gaplayer is made of a plurality of insulating films stacked that are formedby chemical vapor deposition.

A third thin-film magnetic head of the invention comprises: a mediumfacing surface that faces toward a recording medium; a reproducing head;a recording head; and an isolation film for magnetically isolating thereproducing head and the recording head from each other. The reproducinghead incorporates: a magnetoresistive element; a first shield layer anda second shield layer for shielding the magnetoresistive element, theshield layers having portions located on a side of the medium facingsurface and opposed to each other, the magnetoresistive element beingplaced between these portions of the shield layers; a first shield gapfilm, provided between the magnetoresistive element and the first shieldlayer, for insulating the magnetoresistive element and the first shieldlayer from each other; and a second shield gap film, provided betweenthe magnetoresistive element and the second shield layer, for insulatingthe magnetoresistive element and the second shield layer from eachother. The recording head incorporates: a first magnetic layer includinga pole portion and a second magnetic layer including a pole portion, thefirst and second magnetic layers being magnetically coupled to eachother, the pole portions being opposed to each other and placed inregions of the magnetic layers on a side of the medium facing surface,each of the magnetic layers including at least one layer; a gap layerprovided between the pole portions of the first and second magneticlayers; and a thin-film coil at least a part of which is placed betweenthe first and second magnetic layers, the at least part of the coilbeing insulated from the first and second magnetic layers. The isolationfilm is made of a plurality of insulating films stacked that are formedby chemical vapor deposition.

A fourth thin-film magnetic head of the invention comprises: a mediumfacing surface that faces toward a recording medium; a first magneticlayer including a pole portion and a second magnetic layer including apole portion, the first and second magnetic layers being magneticallycoupled to each other, the pole portions being opposed to each other andplaced in regions of the magnetic layers on a side of the medium facingsurface, each of the magnetic layers including at least one layer; a gaplayer provided between the pole portions of the first and secondmagnetic layers; a thin-film coil at least a part of which is placedbetween the first and second magnetic layers, the at least part of thecoil being insulated from the first and second magnetic layers; and acoil insulating layer for insulating neighboring ones of turns of thecoil from each other. The coil insulating layer is made of a pluralityof insulating films stacked that are formed by chemical vapordeposition.

According to the first to fourth thin-film magnetic heads of theinvention, one of the first and second shield gap films, the gap layer,the isolation film, or the coil insulating layer is made of a pluralityof insulating films stacked that are formed by chemical vapordeposition, and exhibits high quality.

According to the first to fourth thin-film magnetic heads of theinvention, the insulating films formed by chemical vapor deposition maybe alumina films.

A first method of the invention is provided for manufacturing athin-film magnetic head comprising: a medium facing surface that facestoward a recording medium; a magnetoresistive element; a first shieldlayer and a second shield layer for shielding the magnetoresistiveelement, the shield layers having portions located on a side of themedium facing surface and opposed to each other, the magnetoresistiveelement being placed between these portions of the shield layers; afirst shield gap film, provided between the magnetoresistive element andthe first shield layer, for insulating the magnetoresistive element andthe first shield layer from each other; and a second shield gap film,provided between the magnetoresistive element and the second shieldlayer, for insulating the magnetoresistive element and the second shieldlayer from each other. The method includes the steps of: forming thefirst shield layer; forming the first shield gap film on the firstshield layer; forming the magnetoresistive element on the first shieldgap film; forming the second shield gap film on the magnetoresistiveelement; and forming the second shield layer on the second shield gapfilm. At least one of the first and second shield gap films is formed bystacking a plurality of insulating films formed by chemical vapordeposition.

A second method of the invention is provided for manufacturing athin-film magnetic head comprising: a medium facing surface that facestoward a recording medium; a first magnetic layer including a poleportion and a second magnetic layer including a pole portion, the firstand second magnetic layers being magnetically coupled to each other, thepole portions being opposed to each other and placed in regions of themagnetic layers on a side of the medium facing surface, each of themagnetic layers including at least one layer; a gap layer providedbetween the pole portions of the first and second magnetic layers; and athin-film coil at least a part of which is placed between the first andsecond magnetic layers, the at least part of the coil being insulatedfrom the first and second magnetic layers. The method includes the stepsof: forming the first magnetic layer; forming the gap layer on the firstmagnetic layer; forming the second magnetic layer on the gap layer; andforming the thin-film coil. The gap layer is formed by stacking aplurality of insulating films formed by chemical vapor deposition.

A third method of the invention is provided for manufacturing athin-film magnetic head comprising: a medium facing surface that facestoward a recording medium; a reproducing head; a recording head; and anisolation film for magnetically isolating the reproducing head and therecording head from each other. The reproducing head incorporates: amagnetoresistive element; a first shield layer and a second shield layerfor shielding the magnetoresistive element, the shield layers havingportions located on a side of the medium facing surface and opposed toeach other, the magnetoresistive element being placed between theseportions of the shield layers; a first shield gap film, provided betweenthe magnetoresistive element and the first shield layer, for insulatingthe magnetoresistive element and the first shield layer from each other;and a second shield gap film, provided between the magnetoresistiveelement and the second shield layer, for insulating the magnetoresistiveelement and the second shield layer from each other. The recording headincorporates: a first magnetic layer including a pole portion and asecond magnetic layer including a pole portion, the first and secondmagnetic layers being magnetically coupled to each other, the poleportions being opposed to each other and placed in regions of themagnetic layers on a side of the medium facing surface, each of themagnetic layers including at least one layer; a gap layer providedbetween the pole portions of the first and second magnetic layers; and athin-film coil at least a part of which is placed between the first andsecond magnetic layers, the at least part of the coil being insulatedfrom the first and second magnetic layers. The method includes the stepsof: forming the reproducing head; forming the recording head; andforming the isolation film. The isolation film is formed by stacking aplurality of insulating films formed by chemical vapor deposition.

A fourth method of the invention is provided for manufacturing athin-film magnetic head comprising: a medium facing surface that facestoward a recording medium; a first magnetic layer including a poleportion and a second magnetic layer including a pole portion, the firstand second magnetic layers being magnetically coupled to each other, thepole portions being opposed to each other and placed in regions of themagnetic layers on a side of the medium facing surface, each of themagnetic layers including at least one layer; a gap layer providedbetween the pole portions of the first and second magnetic layers; athin-film coil at least a part of which is placed between the first andsecond magnetic layers, the at least part of the coil being insulatedfrom the first and second magnetic layers; and a coil insulating layerfor insulating neighboring ones of turns of the coil from each other.The method includes the steps of: forming the first magnetic layer;forming the gap layer on the first magnetic layer; forming the secondmagnetic layer on the gap layer; forming the thin-film coil; and formingthe coil insulating layer. The coil insulating layer is formed bystacking a plurality of insulating films formed by chemical vapordeposition.

According to the first to fourth methods of the invention, theinsulating films formed by the chemical vapor deposition may be aluminafilms.

According to the first to fourth methods of the invention, the chemicalvapor deposition may be low pressure chemical vapor deposition, or maybe plasma chemical vapor deposition or atmospheric pressure chemicalvapor deposition.

According to the first to fourth methods of the invention, theinsulating films formed by the chemical vapor deposition may be formedthrough the use of a plurality of chambers.

According to the first to fourth methods of the invention, theinsulating films formed by the chemical vapor deposition may be formedthrough intermittently injecting a material for making the films. Inthis case, the insulating films formed by the chemical vapor depositionmay be alumina films formed through intermittently injecting H₂O, N₂O orH₂O₂ which is the material for making the films and Al(CH₃)₃ or AlCl₃which is the material for making the films in an alternate manner.

According to the first to fourth methods of the invention, theinsulating films formed by the chemical vapor deposition may be formedat a temperature in a range of 100 to 350° C.

Other and further objects, features and advantages of the invention willappear more fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A and FIG. 1B are cross sections for illustrating a step in amethod of manufacturing a thin-film magnetic head of a first embodimentof the invention.

FIG. 2A and FIG. 2B are cross sections for illustrating a step thatfollows FIG. 1A and FIG. 1B.

FIG. 3A and FIG. 3B are cross sections for illustrating a step thatfollows FIG. 2A and FIG. 2B.

FIG. 4A and FIG. 4B are cross sections for illustrating a step thatfollows FIG. 3A and FIG. 3B.

FIG. 5A and FIG. 5B are cross sections for illustrating a step thatfollows FIG. 4A and FIG. 4B.

FIG. 6A and FIG. 6B are cross sections for illustrating a step thatfollows FIG. 5A and FIG. 5B.

FIG. 7A and FIG. 7B are cross sections for illustrating a step thatfollows FIG. 6A and FIG. 6B.

FIG. 8A and FIG. 8B are cross sections of the thin-film magnetic head ofthe first embodiment.

FIG. 9 is a top view of the thin-film magnetic head of the firstembodiment.

FIG. 10 illustrates a first example of a method of forming a multilayerCVD insulating film of the first embodiment of the invention.

FIG. 11 illustrates a second example of the method of forming themultilayer CVD insulating film of the first embodiment.

FIG. 12 is a plot for showing the result of experiment performed forcomparing the insulation strength of an insulating film formed throughsputtering and that of the multilayer CVD insulating film of the firstembodiment of the invention.

FIG. 13 is a plot for illustrating an example of waveform of readingoutput of the thin-film magnetic head of the first embodiment.

FIG. 14A and FIG. 14B are cross sections of a thin-film magnetic head ofa second embodiment of the invention.

FIG. 15A and FIG. 15B are cross sections of a thin-film magnetic head ofa third embodiment of the invention.

FIG. 16A and FIG. 16B are cross sections for illustrating a step in amethod of manufacturing a thin-film magnetic head of related art.

FIG. 17A and FIG. 17B are cross sections for illustrating a step thatfollows FIG. 16A and FIG. 16B.

FIG. 18A and FIG. 18B are cross sections for illustrating a step thatfollows FIG. 17A and FIG. 17B.

FIG. 19A and FIG. 19B are cross sections for illustrating a step thatfollows FIG. 18A and FIG. 18B.

FIG. 20A and FIG. 20B are cross sections for illustrating a step thatfollows FIG. 19A and FIG. 19B.

FIG. 21A and FIG. 21B are cross sections for illustrating a step thatfollows FIG. 20A and FIG. 20B.

FIG. 22A and FIG. 22B are cross sections for illustrating a step thatfollows FIG. 21A and FIG. 21B.

FIG. 23 is a top view of the related-art thin-film magnetic head.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the invention will now be described in detailwith reference to the accompanying drawings.

First Embodiment

Reference is now made to FIG. 1A to FIG. 8A, FIG. 1B to FIG. 8B, andFIG. 9 to describe a thin-film magnetic head and a method ofmanufacturing the same of a first embodiment of the invention. FIG. 1Ato FIG. 8A are cross sections each orthogonal to the air bearingsurface. FIG. 1B to FIG. 8B are cross sections of the pole portions ofthe head parallel to the air bearing surface.

In the method, as shown in FIG. 1A and FIG. 1B, an insulating layer 2made of alumina (Al₂O₃), for example, of about 5 to 10 μm in thicknessis deposited on a substrate 1 made of aluminum oxide and titaniumcarbide (Al₂O₃-TiC), for example. Next, on the insulating layer 2, abottom shield layer 3 is formed for the reproducing head. The bottomshield layer 3 is made of a magnetic material and has a thickness of 2to 3 μm, for example.

Next, as shown in FIG. 2A and FIG. 2B, a shield gap film 4 a as aninsulating film having a thickness of 10 to 15 nm, for example, isformed on the bottom shield layer 3. The shield gap film 4 a is made ofthe insulating film in which a plurality of thin alumina films arestacked, each of the alumina films being formed through chemical vapordeposition (CVD). This insulating film is hereinafter called themultilayer CVD insulating film. The method of forming the shield gaplayer 4 a will be described later in detail.

Next, a shield gap film 4 b, as an insulating film made of an insulatingmaterial such as alumina, having a thickness of 100 nm, for example, isformed on the shield gap film 4 a except a region where a GMR elementdescribed later will be formed. The shield gap film 4 b may be aninsulating film formed through sputtering or a multilayer CVD insulatingfilm. The shield gap film 4 b is provided for preventing a short circuitbetween the GMR element and the bottom shield layer 3.

Next, on the shield gap film 4 b, a film having a thickness of 40 to 50nm, for example, for making up the GMR element for reproduction isformed through a method such as sputtering. This film is etched with aphotoresist pattern not shown as a mask to form the GMR element 5.

Next, a pair of conductive layers (that may be called leads) 6 areformed by liftoff through the use of the above-mentioned photoresistpattern. The conductive layers 6 are electrically connected to the GMRelement 5. The photoresist pattern is then removed.

Next, as shown in FIG. 3A and FIG. 3B, a shield gap film 7 a, as aninsulating film, having a thickness of 10 to 20 nm, for example, isformed on the shield gap films 4 a and 4 b, the GMR element 5 and theconductive layers 6. The GMR element 5 is embedded in the shield gapfilms 4 a and 7 a. The shield gap film 7 a is made of a multilayer CVDinsulating film. The method of forming the shield gap film 7 a will bedescribed later in detail.

Next, a shield gap film 7 b as an insulating film made of an insulatingmaterial such as alumina and having a thickness of 100 nm, for example,is formed on the shield gap film 7 a except the neighborhood of the GMRelement 5. The shield gap film 7 b may be an insulating film formedthrough sputtering or a multilayer CVD insulating film. The shield gapfilm 7 b is provided for preventing a short circuit between the GMRelement 5 and a top shield layer described later.

Next, as shown in FIG. 4A and FIG. 4B, on the shield gap films 7 a and 7b, a top-shield-layer-cum-bottom-pole-layer (called a top shield layerin the following description) 8 is formed. The top shield layer 8 has athickness of about 3 μm and is made of a magnetic material and used forboth the reproducing head and the recording head.

Next, as shown in FIG. 5A and FIG. 5B, a recording gap layer 9 made ofan insulating film such as an alumina film and having a thickness of 0.1to 0.2 μm, for example, is formed on the top shield layer 8. The gaplayer 9 may be an insulating film formed through sputtering or amultilayer CVD insulating film.

Next, on the recording gap layer 9, a thin-film coil 10 made of copper(Cu), for example, is formed through plating, for example, for theinduction-type recording head. For example, the line width of the coil10 is 0.5 to 0.8 μm, the space between neighboring ones of turns of thecoil 10 is 0.5 μm, and the thickness of the coil 10 is 0.8 to 1.5 μm.

Next, a photoresist layer 11 is formed into a specific shape on therecording gap layer 9 and the coil 10. An end of the photoresist layer11 facing toward the air bearing surface (the medium facing surface thatfaces toward a recording medium) 30 defines the throat height.

Next, as shown in FIG. 6A and FIG. 6B, a portion of the recording gaplayer 9 located in the center of the region where the thin-film coil 10is formed is selectively etched to form a contact hole for making amagnetic path.

Next, a pole portion layer 12 a including the pole portion of the toppole layer 12 is formed in a region extending from the top of a part ofthe recording gap layer 9 located in the pole portion to a part of thephotoresist layer 11 close to the air baring surface 30. The poleportion layer 12 a has a thickness of 2.5 to 3.5 μm, for example. At thesame time, a magnetic layer 12 b having a thickness of 2.5 to 3.5 μm,for example, is formed in the above-mentioned contact hole. The top polelayer 12 is made up of the pole portion layer 12 a and the magneticlayer 12 b and a yoke portion layer described later. The magnetic layer12 b is provided for connecting the yoke portion layer to the top shieldlayer 8.

The pole portion layer 12 a and the magnetic layer 12 b of the top polelayer 12 may be made of NiFe (80 weight % Ni and 20 weight % Fe), orNiFe (45 weight % Ni and 55 weight % Fe) as a high saturation fluxdensity material and formed through plating, or may be made of amaterial such as FeN or FeZrN as a high saturation flux density materialthrough sputtering. Alternatively, a material such as CoFe or a Co-baseamorphous material as a high saturation flux density material may beused.

Next, the recording gap layer 9 and a part of the top shield layer 8 areetched through ion milling, for example, using the pole portion layer 12a as a mask. As shown in FIG. 7B, the structure is called a trimstructure wherein the sidewalls of the top pole portion (the poleportion layer 12 a), the recording gap layer 9, and a part of the topshield layer 8 are formed vertically in a self-aligned manner. The trimstructure suppresses an increase in the effective track width due toexpansion of a magnetic flux generated during writing in a narrow track.

Next, an insulating layer 13 of alumina, for example, having a thicknessof about 4 μm is formed over the entire surface. The insulating layer 13is polished through chemical mechanical polishing (CMP), for example, tothe surfaces of the pole portion layer 12 a and the magnetic layer 12 band flattened.

Next, as shown in FIG. 8A and FIG. 8B, the yoke portion layer 12 c ofthe top pole layer 12 made of a magnetic material for the recording headis formed on the pole portion layer 12 a, the insulating layer 13 andthe magnetic layer 12 b. The yoke portion layer 12 c has a thickness of3 μm, for example. The yoke portion layer 12 c may be made of NiFe (80weight % Ni and 20 weight % Fe) or a high saturation flux densitymaterial such as NiFe (45 weight % Ni and 55 weight % Fe) throughplating, or may be made of a material such as FeN or FeZrN as a highsaturation flux density material through sputtering. Alternatively, amaterial such as CoFe or a Co-base amorphous material as a highsaturation flux density material may be used. To improve the highfrequency characteristic, the yoke portion layer 12 c may be made of anumber of layers of inorganic insulating films and magnetic layers ofPermalloy, for example.

Next, an overcoat layer 14 of alumina, for example, having a thicknessof 20 to 40 μm, for example, is formed to cover the top pole layer 12.Finally, machine processing of the slider including the forgoing layersis performed to form the air bearing surface 30 of the thin-filmmagnetic head including the recording head and the reproducing head. Thethin-film magnetic head is thus completed.

FIG. 9 is a top view of the thin-film magnetic head shown in FIG. 8A andFIG. 8B. The overcoat layer 14 and the other insulating layers and filmare omitted in FIG. 9. The pole portion of the pole portion layer 12 alocated on a side of the air bearing surface 30 has a width equal to thetrack width of the recording head.

In this embodiment the bottom shield layer 3 corresponds to the firstshield layer of the invention. The top shield layer 8 corresponds to thesecond shield layer of the invention. Since the top shield layer 8functions as the bottom pole layer, too, the top shield layer 8corresponds to the first magnetic layer of the invention, too. The toppole layer 12 corresponds to the second magnetic layer of the invention,too. The shield gap film 4 a corresponds to the first shield gap film ofthe invention. The shield gap film 7 a corresponds to the second shieldgap film of the invention.

The thin-film magnetic head of this embodiment comprises the air bearingsurface 30, that is, the medium facing surface that faces toward arecording medium, the reproducing head and the recording head(induction-type electromagnetic transducer). The reproducing headincludes the GMR element 5 and the bottom shield layer 3 and the topshield layer 8 for shielding the GMR element 5. Portions of the bottomshield layer 3 and the top shield layer 8 on a side of the air bearingsurface 30 are opposed to each other while the GMR element 5 is placedbetween these portions of the bottom shield layer 3 and the top shieldlayer 8. The reproducing head further includes: the conductive layers 6connected to the GMR element 5; the shield gap films 4 a and 4 bprovided between the bottom shield layer 3 and the GMR element 5together with the conductive layers 6; and the shield gap films 7 a and7 b provided between the top shield layer 8 and the GMR element 5together with the conductive layers 6.

The recording head includes the bottom pole layer (the top shield layer8) and the top pole layer 12 magnetically coupled to each other each ofwhich includes at least one layer. The bottom pole layer and the toppole layer 12 include pole portions opposed to each other and located inregions on a side of the air bearing surface 30. The recording headfurther includes: the recording gap layer 9 placed between the poleportion of the bottom pole layer and the pole portion of the top polelayer 12; and the thin-film coil 10 at least a part of which is placedbetween the bottom pole layer and the top pole layer 12, the at leastpart of the coil 10 being insulated from the bottom pole layer and thetop pole layer 12.

The following is a description of two examples of the method of forminga multilayer CVD insulating film that is utilized as each of the shieldgap films 4 a and 7 a of the embodiment of the invention.

FIG. 10 illustrates the first example of the method of forming amultilayer CVD insulating film. In this example the multilayer CVDinsulating film is formed by performing the step of making a thinalumina film by low pressure CVD a plurality of times. Such a method offorming an insulating film is described in ‘Microelectronic Engineering36’ (1997), pp. 91-94, for example.

In the first example, as shown in FIG. 10, a thin alumina film is formedon a substrate 60 through the use of a low pressure CVD apparatus 50.This substrate 60 means a structure including the substrate 1 and thelayers stacked thereon in the steps preceding formation of theinsulating film to be obtained. In a chamber 51 of the low pressure CVDapparatus 50, a chuck 52 is provided for fixing the object on which thethin film is to be formed. A heater not shown for heating the chuck 52is provided below the chuck 52. The chamber 51 has two nozzles 53 and 54for injecting a material for making thin films into the chamber 51.

In the first example the substrate 60 is fixed on the top surface of thechuck 52 in the chamber 51 of the low pressure CVD apparatus 50. When amultilayer CVD insulating film is formed on the substrate 60, the chuck52 and the substrate 60 are maintained at a temperature in the range of100 to 350° C., or preferably in the range of 150 to 250° C. Therefore,thin alumina films making up the multilayer CVD insulating film areformed at a temperature in the range of 100 to 350° C., or preferably inthe range of 150 to 250° C. The degree of vacuum inside the chamber 51is maintained at about 10-3 to 10-5 Pa.

In the first example the following steps are alternately repeated. Thestep first taken is to inject a material for making a thin film, thatis, H₂O, N₂O or H₂O₂ through the nozzle 53, for example, onto thesubstrate 60 for a short period of time, the material being carried bybubbles of a purge gas of N2. The next step is to inject a material formaking the thin film, that is, Al(CH₃)₃ (trimethylaluminum) or AlCl₃through the nozzle 54, for example, onto the substrate 60 for a shortperiod of time, the material being carried by bubbles of a purge gas ofN₂. In the first example the materials for making thin films areintermittently injected onto the substrate 60. The flow rate of oneinjection of H₂O, N₂O or H₂O₂ is 0.25 to 0.5 mg, for example. The flowrate of one injection of Al(CH₃)₃ or AlCl₃ is 0.1 to 0.2 mg, forexample. One cycle is the combination of one injection of H₂O, N₂O orH₂O₂ and one injection of Al(CH₃)₃ or AlCl₃. The duration of one cycleis about 2 seconds, for example. Through the cycle, an alumina film asthin as 0.1 to 0.2 nm, for example, is formed on the substrate 60 by achemical reaction between H₂O, N₂O or H₂O₂ and Al(CH₃)₃ or AlCl₃. In thefirst example a plurality of cycles are performed to stack a pluralityof thin alumina films. A multilayer CVD insulating film having a desiredthickness is thereby formed.

FIG. 11 illustrates the second example of the method of forming amultilayer CVD insulating film. In this example the multilayer CVDinsulating film is formed by performing the step of making a thinalumina film by CVD a plurality of times through the use of a pluralityof chambers. In the second example, as shown in FIG. 11, thin aluminafilms are formed on the substrate 60 through the use of a multi-chamberCVD apparatus 70. The CVD apparatus 70 comprises a plurality of chambers71 and a transfer device 72 for loading and unloading the object onwhich thin films are to be formed in and out of the chambers 71. Each ofthe chambers 71 is designed to form a desired thin film on the object byplasma CVD, for example.

In the second example the substrate 60 is transferred to one of thechambers 71 by the transfer device 72. In this chamber 71 a thin aluminafilm is formed on the substrate 60 through the use of 02 and Al(CH)₃,for example. The degree of vacuum inside each of the chambers 71 ismaintained at about 103 Pa, for example. The substrate 60 in each of thechambers 71 is maintained at a temperature in the range of 100 to 350°C., or preferably in the range of 200 to 250° C. In each of the chambers71 the alumina film formed on the substrate 60 has a thickness of 0.5 to1.5 nm, for example.

In the second example the substrate 60 on which the thin alumina film isformed as described above is transferred to another one of the chambers71 by the transfer device 72. In this one of the chambers 71 anotheralumina film is formed on the substrate 60 as in the first one of thechambers 71. In the second example the substrate 60 is transferred amongthe chambers 71 in each of which a thin alumina film is formed on thesubstrate 60 in a similar manner. According to the second example asthus described, the step of forming a thin alumina film is performed aplurality of times through the use of a plurality of chambers 71. Amultilayer CVD insulating film is thereby formed.

In the second example atmospheric CVD may be used instead of plasma CVD.The foregoing first and second examples are not limited to theinsulating films making up the shield gap films 4 a and 7 a but may beapplied to the insulating films making up the shield gap films 4 b and 7b and to the insulating film making up the recording gap layer 9.

Compared to an insulating film formed through sputtering, the multilayerCVD insulating film formed through the method such as the foregoingfirst or second example is more closely packed and has a more eventhickness, greater insulation strength and better step coverage owing tothe closely packed structure. Since the multilayer CVD insulating filmhas such qualities, it is possible to reduce the thickness thereofwithout reducing the qualities, compared to the insulating film formedthrough sputtering.

The following is a description of the result of experiment performed forcomparing center line average height Ra of an insulating film formedthrough sputtering and that of the multilayer CVD insulating film of theembodiment of the invention. The center line average height Ra indicatesevenness of the thickness. In this experiment the average height Ra ofthe insulating film formed through sputtering and having a thickness of30 nm, and that of the multilayer CVD insulating film having a thicknessof 30 nm were obtained. The result was that the average height Ra of theinsulating film formed through sputtering was 0.216 nm while the averageheight Ra of the multilayer CVD insulating film was 0.107 nm. Thisresult shows that the evenness of the thickness of the multilayer CVDinsulating film was better than that of the insulating film formedthrough sputtering.

Reference is now made to FIG. 12 to describe the result of experimentperformed for comparing the insulation strength of an insulating filmformed through sputtering and that of the multilayer CVD insulating filmof the embodiment of the invention. FIG. 12 shows the relationshipbetween the voltage applied to four types of insulating films and thepercentage of insulating films in which no puncture occurred (which isindicated as yield in FIG. 12). The four types of insulating films were:an alumina film (indicated as ECR_15 in FIG. 12) having a thickness of15 nm and formed through continuous sputtering through the use of anelectron cyclotron resonance (ECR) sputtering apparatus; an alumina film(indicated as ECR_20 in FIG. 12) having a thickness of 20 nm and formedthrough continuous sputtering through the use of the ECR sputteringapparatus; a multilayer CVD insulating film (indicated as ALCVD_15 inFIG. 12) having a thickness of 15 nm and formed through performing thestep of forming a thin alumina film by low pressure CVD a plurality oftimes; and a multilayer CVD insulating film (indicated as ALCVD_20 inFIG. 12) having a thickness of 20 nm and formed through performing thestep of forming a thin alumina film by low pressure CVD a plurality oftimes.

As shown in FIG. 12, the alumina film formed through continuoussputtering through the use of the ECR sputtering apparatus had aninsulation strength of about 5 volts when the thickness was 20 nm, andan insulation strength of about 3 volts when the thickness was 15 nm.Either case was unpractical since the film was likely to suffer staticdamage. In contrast, the multilayer CVD insulating film had aninsulation strength of 7 volts or greater when the thickness was either20 nm or 15 nm, and it was unlikely to suffer static damage.

According to the embodiment thus described, each of the shield gap films4 a and 7 a is made of the multilayer CVD insulating film made up of aplurality of thin alumina films stacked that are formed by CVD. Asdescribed above, the multilayer CVD insulating film is closely packedand has an even thickness, greater insulation strength and excellentstep coverage. It is thus possible to reduce the thickness thereof. As aresult, according to the embodiment, it is possible to make thethickness of each of the shield gap films 4 a and 7 a smaller than thatof a prior-art shield gap film, and to reduce the shield gap length.Furthermore, a reduction in the shield gap length results in a reductionin half width of the reading output. It is thereby possible to improvethe recording density. FIG. 13 illustrates an example of waveform ofreading output of the thin-film magnetic head of the embodiment, whereinPW50 indicates the half width of the reading output. The half width PW50is a period of time required for the reading output to reach 50% orgreater of the peak value.

The shield gap film 7 a is formed in regions having projections anddepressions, such as the neighborhood of the pattern edge of the GMRelement 5 or the neighborhood of the conductive layers 6 connected tothe GMR element 5. Therefore, pinholes and faulty insulation are likelyto result if step coverage is unsatisfactory. In this embodiment,however, the shield gap film 7 a is made of the multilayer CVDinsulating film that exhibits excellent step coverage. It is therebypossible to prevent pinholes and faulty insulation in the shield gapfilm 7 a.

According to the embodiment, the shield gap films 4 a and 7 a that arethin and have high qualities are formed. It is thereby possible toimprove the yield of thin-film magnetic heads for high densityrecording.

The foregoing features of the embodiment improve the performancecharacteristics and yield of thin-film magnetic heads.

In the embodiment not only the shield gap films 4 a and 7 a but also theshield gap films 4 b and 7 b and the recording gap layer 9 may be madeof multilayer CVD insulating films. It is thereby possible to reduce thethickness of these layers and to improve the qualities thereof, and tofurther improve the characteristics and yield of thin-film magneticheads.

Second Embodiment

Reference is now made to FIG. 14A and FIG. 14B to describe a thin-filmmagnetic head and a method of manufacturing the same of a secondembodiment of the invention. FIG. 14A is a cross section orthogonal tothe air bearing surface. FIG. 14B is a cross section of the poleportions of the head parallel to the air bearing surface.

In place of the top shield layer 8 of the first embodiment, thethin-film magnetic head of the second embodiment comprises: a top shieldlayer 8 a made of a magnetic material; an isolation film 20; and abottom pole layer 8 b made of a magnetic material. The isolation film 20is an insulating film that magnetically isolates the reproducing headand the recording head from each other.

In the method of the second embodiment, the top shield layer 8 a isformed on the shield gap films 7 a and 7 b. Next, the isolation film 20is formed on the top shield layer 8 a. The bottom pole layer 8 b is thenformed on the isolation film 20. The isolation film 20 has a thicknessof 0.1 to 0.2 μm, for example.

The isolation film 20 is made of a multilayer CVD insulating film madeup of a plurality of thin alumina films stacked that are formed by CVD,which is similar to the shield gap films 4 a and 7 a of the firstembodiment.

According to the second embodiment, the isolation film 20 magneticallyisolates the reproducing head and the recording head from each other. Itis thereby possible to reduce noise such as Barkhausen noise of thereproducing head resulting from a writing operation of the recordinghead, and to reduce variations in reading output.

According to the embodiment, the isolation film 20 is made of themultilayer CVD insulating film. The isolation film 20 is therefore thinand of high quality. It is thus possible to improve the performancecharacteristics and yield of thin-film magnetic heads.

The remainder of configuration, functions and effects of the embodimentare similar to those of the first embodiment.

Third Embodiment

Reference is now made to FIG. 15A and FIG. 15B to describe a thin-filmmagnetic head and a method of manufacturing the same of a thirdembodiment of the invention. FIG. 15A is a cross section orthogonal tothe air bearing surface. FIG. 15B is a cross section of the poleportions of the head parallel to the air bearing surface.

In place of the photoresist layer 11 and the insulating layer 13 of thefirst embodiment, the thin-film magnetic head of the third embodimentcomprises a photoresist layer 31 and a coil insulating layer 32. Thephotoresist layer 31 is not formed between the recording gap layer 9 andthe thin-film coil 10, but formed only between the recording gap layer 9and a part of the pole portion layer 12 a of the top pole layer 12. Inthis embodiment the coil 10 is located on the recording gap layer 9. Thecoil insulating layer 32 covers the coil 10 and insulates neighboringones of the turns of the coil 10 from each other. In this embodiment anend of the photoresist layer 3.1 facing toward the air bearing surface30 defines the throat height.

The coil insulating layer 32 is made of a multilayer CVD insulating filmmade up of a plurality of thin alumina films stacked that are formed byCVD, which is similar to the shield gap films 4 a and 7 a of the firstembodiment.

In the method of the third embodiment, the photoresist layer 31 isformed on the recording gap layer 9. Next, the pole portion layer 12 aof the top pole layer 12 is formed on the recording gap layer 9 and thephotoresist layer 31. At the same time, the magnetic layer 12 b isformed in the contact hole formed in the recording gap layer 9. Next,the recording gap layer 9 and a part of the top shield layer 8 areetched by ion milling, for example, with the pole portion layer 12 a asa mask. A trim structure is thereby formed. Next, the thin-film coil 10is formed on the recording gap layer 9. The coil insulating layer 32 ofa multilayer CVD insulating film is then formed over the entire surface.The coil insulating layer 32 is polished through CMP, for example, tothe surfaces of the pole portion layer 12 a and the magnetic layer 12 b,and flattened. The following steps are similar to those of the firstembodiment.

According to the embodiment, the coil insulating layer 32 insulatingneighboring ones of the turns of the coil 10 from each other is made ofthe multilayer CVD insulating film that exhibits excellent stepcoverage. As a result, the insulating film without keyholes and voids isformed to fill the space between neighboring ones of the turns of thecoil 10. It is thereby possible to improve the performancecharacteristics and yield of thin-film magnetic heads.

The remainder of configuration, functions and effects of the thirdembodiment are similar to those of the first embodiment.

The present invention is not limited to the foregoing embodiments butmay be practiced in still other ways. For example, the invention is notlimited to a thin-film magnetic head in which the MR element is a GMRelement but may be applied to a thin-film magnetic head in which the MRelement is an AMR element or a tunnel magnetoresistive (TMR) element.

In the foregoing embodiments, the thin-film magnetic head is disclosed,comprising the MR element for reading formed on the base body and theinduction-type electromagnetic transducer for writing stacked on the MRelement. Alternatively, the MR element may be stacked on theelectromagnetic transducer.

That is, the induction-type electromagnetic transducer for writing maybe formed on the base body and the MR element for reading may be stackedon the transducer. Such a structure may be achieved by forming amagnetic film functioning as the top pole layer of the foregoingembodiments as a bottom pole layer on the base body, and forming amagnetic film functioning as the bottom pole layer of the embodiments asa top pole layer facing the bottom pole layer with the recording gapfilm in between. In this case it is possible that the top pole layer ofthe induction-type electromagnetic transducer functions as the bottomshield layer of the MR element, too.

The invention may be applied to a thin-film magnetic head dedicated toreading that has no induction-type electromagnetic transducer, athin-film magnetic head dedicated to writing that has an induction-typeelectromagnetic transducer only, or a thin-film magnetic head thatperforms reading and writing with an induction-type electromagnetictransducer.

According to the first thin-film magnetic head or the method ofmanufacturing the same of the invention thus described, at least one ofthe first and second shield gap films is made of a plurality ofinsulating films stacked that are formed by chemical vapor deposition.It is thereby possible to improve the quality of at least one of thefirst and second shield gap films, and to improve the performancecharacteristics and yield of thin-film magnetic heads. In addition, theinvention achieves a reduction in shield gap length. Recording densityis thereby improved.

According to the second thin-film magnetic head or the method ofmanufacturing the same of the invention, the gap layer of the recordinghead is made of a plurality of insulating films stacked that are formedby chemical vapor deposition. The gap layer is thus made of a highquality insulating film. It is thereby possible to improve theperformance characteristics and yield of thin-film magnetic heads.

According to the third thin-film magnetic head or the method ofmanufacturing the same of the invention, the isolation film isolatingthe reproducing head from the recording head is made of a plurality ofinsulating films stacked that are formed by chemical vapor deposition.The isolation film is thus made of a high quality insulating film. It isthereby possible to improve the performance characteristics and yield ofthin-film magnetic heads.

According to the fourth thin-film magnetic head or the method ofmanufacturing the same of the invention, the coil insulating layerinsulating neighboring ones of turns of the thin-film coil from eachother is made of a plurality of insulating films stacked that are formedby chemical vapor deposition. The coil insulating layer is thus made ofa high quality insulating film. It is thereby possible to improve theperformance characteristics and yield of thin-film magnetic heads.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

1. A method of manufacturing a thin-film magnetic head comprising: amedium facing surface that faces toward a recording medium; amagnetoresistive element; a first shield layer and a second shield layerfor shielding the magnetoresistive element, the shield layers havingportions located on a side of the medium facing surface and opposed toeach other, the magnetoresistive element being placed between theseportions of the shield layers; a first shield gap film, provided betweenthe magnetoresistive element and the first shield layer, for insulatingthe magnetoresistive element and the first shield layer from each other;and a second shield gap film, provided between the magnetoresistiveelement and the second shield layer, for insulating the magnetoresistiveelement and the second shield layer from each other; the methodincluding the steps of: forming the first shield layer; forming thefirst shield gap film on the first shield layer; forming themagnetoresistive element on the first shield gap film; forming thesecond shield gap film on the magnetoresistive element; and forming thesecond shield layer on the second shield gap film; wherein at least oneof the first and second shield gap films is formed by stacking aplurality of insulating films formed by chemical vapor deposition, andeach of the insulating films has a thickness of 0.1 nm to 0.2 nm.
 2. Themethod according to claim 1, wherein the insulating films formed by thechemical vapor deposition are alumina films.
 3. The method according toclaim 1, wherein the chemical vapor deposition is low pressure chemicalvapor deposition.
 4. The method according to claim 1, wherein thechemical vapor deposition is plasma chemical vapor deposition oratmospheric pressure chemical vapor deposition.
 5. The method accordingto claim 1, wherein the insulating films formed by the chemical vapordeposition are formed through the use of a plurality of chambers suchthat a first one of the insulating films is formed in one of thechambers, and subsequently a next one of the insulating films is formedin another one of the chambers.
 6. The method according to claim 1,wherein the insulating films formed by the chemical vapor deposition areformed through intermittently injecting a material for making the films.7. The method according to claim 6, wherein the insulating films formedby the chemical vapor deposition are alumina films formed throughintermittently injecting a first material for making the films and asecond material for making the films in an alternate manner, wherein thefirst material is a material selected from the group consisting of H₂O,N₂O and H₂O₂, and the second material is a material selected from thegroup consisting of Al(CH₃)₃ and AlCl₃.
 8. The method according to claim1, wherein the insulating films formed by the chemical vapor depositionare formed at a temperature in a range of 100 to 350° C.